Bone marrow dendritic cells are reduced in patients with high-risk myelodysplastic syndromes.

Dendritic cells (DC) are antigen-presenting cells that play a pivotal role in coordinating functions of the immune system. Previous studies suggest that bone marrow (BM) failure in myelodysplastic syndromes (MDS) may be in part immune-mediated, and that the high propensity for relapse may reflect decreased immune surveillance. This study aimed to assess the frequency of DC in BM samples from well-annotated untreated MDS patients by using 4-colour flow cytometry. DC levels were markedly reduced in all subtypes of MDS. The clinical impact of this finding on therapy response and relapse after, e.g. allogeneic stem cell transplantation warrants further investigation.